DS analyzer: Java Maven support - Manifest scanning: pom.xml scanning
## Description
This implementation issue covers adding `pom.xml` manifest scanning capabilities to the Dependency Scanning (DS) analyzer. **This manifest scanning will serve as a fallback mechanism when lock files are not available.**
## Scope
**Objective:** Implement manifest scanning functionality for Maven `pom.xml` files
**Key Components:**
* Add `pom.xml` file detection and parsing logic
* Implement dependency extraction from Maven manifest files
* Integrate with existing DS analyzer workflow as a fallback option
* Ensure compatibility with the current dependency scanning pipeline
**Acceptance Criteria:**
* DS analyzer successfully detects and processes `pom.xml` files
* Direct dependencies are correctly extracted and reported
## Related Issues
* Spike: https://gitlab.com/gitlab-org/gitlab/-/work_items/584568
issue